A pair of R&B musicians have filed a $10-million copyright infringement lawsuit against Justin Bieber and Usher, claiming that Bieber’s 2010 hit “Somebody to Love” was based on a song they wrote but were not credited for.

Singer Devin Copeland, who performs under the name De Rico, and songwriter Mareio Overton filed the suit last week in U.S. District Court in Virginia, alleging that they pitched their song to Usher in 2009, heard nothing back, but then heard Bieber’s song on the radio the following year. Bieber, songwriter Heather Bright and the Stereotypes are credited as the writer of his hit.

"There is essentially a zero probability for the number of points of congruence between the two versions of 'Somebody to Love,' " Copeland and Overton said in the lawsuit.

Representatives for Bieber and Usher so far have not commented on the suit.

Bieber is managed by a firm controlled by Usher. The suit lists 19 defendants, also including Universal Music, the parent company of Bieber’s label. “Somebody to Love” peaked at No. 15 during an 18-week run on the Billboard Top 100.

Usher recorded the song as a demo for his 2010 album “Raymond v. Raymond” and subsequently did a remix with Bieber singing backing vocals.